As demand for a mobile communication has been increasing, development of many wireless networks has been performed. Also, in order to provide a seamless service of such heterogeneous wireless networks, various discussions and technology developments of a next generation network (NGN) have been proceeding.
The wireless network includes a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a wireless LAN network, a wireless personal area network (WPAN), a general packet radio service (GPRS) system, a wireless fidelity (WiFi) system, a worldwide interoperability for microwave access (WiMAX) system, and a code division multiple access (CDMA) 2000 system. WiFi indicates a particular type of a WLAN which uses IEEE 802.11-related specifications. WiMAX indicates a type of a broadband wireless access based on the IEEE 802.16 standard for MAN. Such wireless network systems enable communications among various mobile stations such as a personal computer, a mobile phone, or a portable communication terminal. Above-described wireless network system further includes at least one bridge element such as an access point or an access node where entry/exit of user traffic is performed.
In the case that the above-described various wireless network technologies are developed and embodied, an issue of compatibility among at least two different wireless networks is raised. Namely, technology providing an individual mobile station with Internet protocol (IP) address for compatibility among different wireless systems, which is entitled as All-IP technology, is limited. Also, various related technology issues such as development of the Internet protocol version 6 (IPv6) for enlarging an address resource under the All-IP technology, a neighbor network discovery technology under the IPv6, and an improved technology of a mobility service including a handover under the IPv6 are proposed. Particularly, the neighbor network discovery method of the mobile station (MS) which is located in at least two different wireless networks in the All-IP environment is problematic. As an example, a neighbor network discovery technology may be required to determine which wireless networks in the heterogeneous wireless network environment including a WiFi network, a WiMAX network, and a CDMA 2000 network that the MS will access to and perform a handover with.
As described above, studies to discover a capability and configuration information with respect to the neighbor network have been advancing. The study includes a solution of using a media access control (MAC) layer design. However, the design may provide only a portion of information which is necessary for simplifying the entire discovery. Also, as an example, an IEEE 802.11k solution for the WLAN may not be generally applied to the different wireless network systems except for an IEEE 802.11 link. Also, the solution through the MAC layer design may not be easily applied to a legacy network. Similarly, a portion of information about the neighbor network may be obtained by operations of a few particular protocols. For example, a portion of information about the neighbor network may be obtained by using a protocol like a proxy router discovery. In this instance, the proxy router is used in a mobile IPv6 fast handover. However, the method using the proxy router also has a restricted applicability. Also, the method using the proxy router may not satisfy needs such as applicability to the All-IP environment, a discovery of all neighbor networks around the MS, and an extensive learning about capability/configuration information of the neighbor network in the MS.
Currently, the IEEE 802.21 Working Group has made various proposals for inter-operability among different wireless networks, such as supporting of a fast handover in the All-IP environment. However, the IEEE 802.21 Working Group may not have proposed a technical solution to the questions: in which way does the MS request the neighbor network discovery; which entity responds to a request for the neighbor network discovery; and, in which message format is a corresponding request and reply transceived.
Accordingly, a method for discovering neighbor networks in the MS and a system for enabling the method which are available in a next generation network system that the All-IP technology will be commonly included in, is provided.